I've been tuning some HH 500 spine arrows. Gold Tip states that these will be stiff, well, not so much I'm finding. In fact when all was said and done they tune exactly the same as 3 Rivers Trad Only 500 shafts when shot from my HHA Redman, 68" 50#28". Arrows are 29" with 200 - 225 gr out front.
Tried the same arrows on my HHA Sirocco, 70" 52#@28" and they were way weak. That bow is more center cut and smokes. She purrs with 5575's with the same weight in on the front oddly enough.